What the dimensions mean
In the 125/90 configuration, nominal dimensions are 125 mm for gutters and 90 mm for downpipes. The 150/100 system uses 150 mm and 100 mm dimensions. Selection depends on drained area, roof geometry and outlet positions.
A single rule based on house area is insufficient. Similar roofs can need different downpipe numbers and layouts.
Include all components
Alongside gutters and downpipes, a quotation may include brackets, end caps, corners, outlets, elbows, clips, extensions and discharge components. Quantities follow actual lengths and routes.
Colour and finish can be coordinated with the covering. Do not equate rainwater-system warranty with metal-tile warranty; check the certificate for the ordered product family.
Which dimensions help
Measure eave lengths, approximate height to ground and corner count. Note possible discharge locations and any existing collection system. Avoid climbing onto the roof solely for this estimate.
Send a sketch and your Craiova or Dolj project location. The final configuration is checked against installation and water discharge arrangements.